Photosensor and photosensor system

Abstract

A photosensor array is provided with one or more semiconductor layers having carrier generating regions for generating carriers by incident exciting light, and the positions of the carrier generating regions are set arbitrarily so as to equalize the balance of incident light in the direction of two-dimensional travel, so that sensing with less distortion can be achieved.

What is claimed is:  
     
       1. A photosensor system comprising: 
       (a) a plurality of photosensors, each including:  
       a first gate electrode,  
       a first gate insulating film provided above said first gate electrode,  
       source and drain electrodes provided above said first gate insulating film,  
       a semiconductor layer provided between said source and drain electrodes, and having a carrier generating region for generating carriers by incident exciting light and a plurality of channel regions separated from each other so as to prevent an electric field between said source and drain electrodes from concentrating,  
       first and second impurity doped layers respectively connected to the source and drain electrodes, and separated from each other such that the first and second impurity doped lavers define a channel therebetween in the semiconductor layer, and such that a distance between the first and second impurity doped layers is constant at any part of the channel for matching a length of the channel;  
       a second gate insulating film provided above said semiconductor layer, and  
       a second gate electrode provided above said second gate insulating film;  
       (b) a first gate line connecting said first gate electrodes of said photosensors to each other; and  
       (c) a second gate line connecting said second gate electrodes of said photosensors to each other and arranged apart from said first gate line in a plane between adjacent photosensors.  
     
     
       2. The photosensor system according to  claim 1 , wherein said second gate line is made of material that allows said exciting light to pass through. 
     
     
       3. The photosensor system according to  claim 1 , wherein said second gate line is formed integrally with said second gate electrode. 
     
     
       4. The photosensor system according to  claim 1 , further comprising a first gate driver for supplying a signal to said first gate line for selectively bringing said photosensors into one of a selection state and a non-selection state, and a second gate driver for supplying a signal to said second gate line for selectively bringing said photosensors into one of a reset state and a carrier accumulated state. 
     
     
       5. A photosensor system comprising: 
       (a) a plurality of photosensors arranged in a matrix, with an interval between adjacent photosensors in a row direction being equal in length to an interval between the adjacent photosensors in a column direction, each photosensor including:  
       a first gate electrode,  
       a first gate insulating film provided above said first gate electrode,  
       source and drain electrodes provided above said first gate insulating film,  
       a semiconductor layer provided between said source and drain electrodes, and having a plurality of carrier generating regions for generating carriers by incident exciting light and a plurality of channel regions separated from each other so as to prevent an electric field between said source and drain electrodes from concentrating,  
       first and second impurity doped layers respectively connected to the source and drain electrodes, and separated from each other such that the first and second impurity doped layers define a channel therebetween in the semiconductor layer, and such that a distance between the first and second impurity doped layers is constant at any tart of the channel for matching a length of the channel;  
       a second gate insulating film provided above said semiconductor layer, and  
       a second gate electrode provided above said second gate insulating film;  
       (b) source lines connected to the source electrodes of said photosensors arranged in a first direction;  
       (c) drain lines connected to the drain electrodes of said photosensors arranged in said first direction;  
       (d) first gate lines connected to the first gate electrodes of said photosensors arranged in a second direction;  
       (e) second gate lines connected to the second gate electrodes of said photosensors arranged in said second direction;  
       (f) precharging means for outputting a precharge voltage to said drain lines;  
       (g) reading means for reading the precharge voltage, as varied according to incident light on said photosensors;  
       (h) a first gate driver for supplying a signal to said first gate lines for selectively bringing said photosensors into one of a selection state and a non-selection state; and  
       (i) a second gate driver for supplying a signal to said second gate lines for selectively bringing said photosensors into one of a reset state and a carrier accumulated state.  
     
     
       6. The photosensor system according to  claim 5 , further comprising a light source for emitting light including said exciting light. 
     
     
       7. A photosensor system comprising: 
       (a) a plurality of photosensors arranged in a matrix, with an interval between adjacent photosensors in a row direction being equal in length to an interval between the adjacent photosensors in a column direction, each photosensor including:  
       a first gate electrode,  
       a first gate insulating film provided above said first gate electrode,  
       source and drain electrodes provided above said first gate insulating film,  
       a plurality of semiconductor layers provided between is said source and drain electrodes, and each having a carrier generating region for generating carriers by incident exciting light and a channel region, said channel regions being arranged so that there is distance between the channel regions for preventing an electric field between said source and drain electrodes from concentrating,  
       first and second impurity doped layers respectively connected to the source and drain electrodes, and separated from each other such that the first and second impurity doped layers define the channel region therebetween in each of the semiconductor layers, and such that a distance between the first and second impurity doped layers is constant at any part of the channel region for matching a length of the channel region;  
       a second gate insulating film provided above said semiconductor layers, and  
       a second gate electrode provided above said second gate insulating film;  
       (b) source lines connected to the source electrodes of said photosensors arranged in a first direction;  
       (c) drain lines connected to the drain electrodes of said photosensors arranged in said first direction;  
       (d) first gate lines connected to the first gate electrodes of said photosensors arranged in a second direction;  
       (e) second gate lines connected to the second gate electrodes of said photosensors arranged in said second direction;  
       (f) precharging means for outputting a precharge voltage to said drain lanes;  
       (g) reading means for reading the precharge voltage, as varied according to incident light on said photosensors;  
       (h) a first gate driver for supplying a signal to said first gate lines for selectively bringing said photosensors into one of a selection state and a non-selection state; and  
       (i) a second gate driver for supplying a signal to said second gate lines for selectively bringing said photosensors into one of a reset state and a carrier accumulated state.  
     
     
       8. The photosensor system according to  claim 7 , further comprising a light source for emitting light including said exciting light. 
     
     
       9. A photosensor system comprising: 
       (a) a plurality of photosensors arranged in a matrix, with an interval between adjacent photosensors in a row direction being equal in length to an interval between the adjacent photosensors in a column direction, each photosensor including:  
       a first gate electrode,  
       a first gate insulating film provided above said first gate electrode,  
       source and drain electrodes provided above said first gate insulating film,  
       a plurality of semiconductor layers provided between said source and drain electrodes, and each having a plurality of carrier generating regions for generating carriers by incident exciting light and a plurality of channel regions, said plurality of channel regions being arranged so that there is distance between the channel regions for preventing an electric field between said source and drain electrodes from concentrating,  
       first and second impurity doped layers respectively connected to the source and drain electrodes, and separated from each other such that the first and second impurity dosed layers define the channel region therebetween in each of the semiconductor layers, and such that a distance between the first and second impurity doped layers is constant at any part of the channel region for matching a length of the channel region;  
       a second gate insulating film provided above said semiconductor layers, and  
       a second gate electrode provided above said second gate insulating film;  
       (b) source lines connected to the source electrodes of said photosensors arranged in a first direction;  
       (c) drain lines connected to the drain electrodes of said photosensors arranged in said first direction;  
       (d) first gate lines connected to the first gate electrodes of said photosensors arranged in a second direction;  
       (e) second gate lines connected to the second gate electrodes of said photosensors arranged in said second direction;  
       (f) precharging means for outputting a precharge voltage to said drain lines;  
       (g) reading means for reading the precharge voltage, as varied according to incident light on said photosensors;  
       (h) a first gate driver for supplying a signal to said first gate lines for selectively bringing said photosensors into one of a selection state and a non-selection state; and  
       (i) a second gate driver for supplying a signal to said second gate lines for selectively bringing said photosensors into one of a reset state and a carrier accumulated state.  
     
     
       10. The photosensor system according to  claim 9 , further comprising a light source for emitting light including said exciting light. 
     
     
       11. A photosensor system comprising: 
       a plurality of photosensors arranged in a matrix, with an interval between adjacent photosensors in a row direction being equal in length to an interval between the adjacent photosensors in a column direction, each photosensor including:  
       a first gate electrode for selectively bringing said photosensors into one of selection state and a non-selection state,  
       a first gate insulating film provided above said first gate electrode,  
       source and drain electrodes provided above said first gate insulating film,  
       a semiconductor layer provided between said source and drain electrodes, and having a plurality of channel regions separated from each other so as to prevent an electric field between said source and drain electrodes from concentrating,  
       first and second impurity doped layers respectively connected to the source and drain electrodes, and separated from each other such that the first and second impurity dosed layers define the channel region therebetween in the semiconductor layer, and such that a distance between the first and second impurity doped layers is constant at any part of the channel region for matching a length of the channel region;  
       a second gate insulating film provided above said semiconductor layer, and  
       a second gate electrode for selectively bringing said photosensors into one of a reset state and a carrier accumulated state, said second gate electrode being provided above said second gate insulating film.  
     
     
       12. A photosensor system comprising: 
       a plurality of photosensors arranged in a matrix, with an interval between adjacent photosensors in a row direction being equal in length to an interval between the adjacent photosensors in a column direction, each photosensor including:  
       a first gate electrode for selectively bringing said photosensors into one of a selection state and a non-selection state,  
       a first gate insulating film provided above said first gate electrode,  
       source and drain electrodes provided above said first gate insulating film,  
       a plurality of semiconductor layers provided between said source and drain electrodes, and each having a channel region, said channel regions being arranged so that there is distance between the channel regions for preventing an electric field between said source and drain electrodes from concentrating,  
       first and second impurity doped layers respectively connected to the source and drain electrodes, and separated from each other such that the first and second impurity doped layers define the channel region therebetween in each of the semiconductor layers, and such that a distance between the first and second impurity doped layers is constant at any part of the channel region for matching a length of the channel region;  
       a second gate insulating film provided above said semiconductor layers, and  
       a second gate electrode for selectively bringing said photosensors into one of a reset state and a carrier accumulated state, said second gate electrode being provided above said second gate insulating film.  
     
     
       13. A photosensor system comprising: 
       a plurality of photosensors arranged in a matrix, with an interval between adjacent photosensors in a row direction being equal in length to an interval between the adjacent photosensors in a column direction, each photosensor including:  
       a first gate electrode for selectively bringing said photosensors into one of a selection state and a non-selection state,  
       a first gate insulating film provided above said first gate electrode,  
       source and drain electrodes provided above said first gate insulating film,  
       a plurality of semiconductor layers provided above said first gate insulating film, and each having a plurality of channel regions arranged so that there is distance between the channel regions for preventing an electric field between said source and drain electrodes from concentrating,  
       first and second impurity doped layers respectively connected to the source and drain electrodes, and separated from each other such that the first and second impurity doped layers define the channel region therebetween in each of the semiconductor layers, and such that a distance between the first and second impurity doped layers is constant at any part of the channel region for matching a length of the channel region;  
       a second gate insulating film provided above said semiconductor layers, and  
       a second gate electrode for selectively bringing said photosensors into one of a reset state and a carrier accumulated state, said second gate electrode being provided above said second gate insulating film.  
     
     
       14. A photosensor comprising: 
       a first gate electrode;  
       a first gate insulating film provided above said first gate electrode;  
       source and drain electrodes provided above said first gate insulating film;  
       a semiconductor layer provided between said source and drain electrodes, and having a plurality of channel regions separated from each other so as to prevent an electric field between said source and drain electrodes from concentrating;  
       first and second impurity doped lavers respectively connected to the source and drain electrodes, and separated from each other such that the first and second impurity doped layers define a channel therebetween in the semiconductor layer, and such that a distance between the first and second impurity doped layers is constant at any part of the channel for matching a length of the channel;  
       a second gate insulating film provided above said semiconductor layer; and  
       a second gate electrode provided above said second gate insulating film.  
     
     
       15. The photosensor according to  claim 14 , wherein said channel regions are arranged side by side. 
     
     
       16. The photosensor according to  claim 14 , wherein each of channel lengths of said channel regions equals in length. 
     
     
       17. The photosensor according to  claim 14 , wherein each of said channel regions equals in shape. 
     
     
       18. The photosensor according to  claim 14 , wherein said semiconductor layer has a plurality of carrier generating regions for generating carriers when struck by exciting light. 
     
     
       19. The photosensor according to  claim 18 , wherein said carrier generating regions are arranged side by side in a direction of a channel length of at least one of said channel regions. 
     
     
       20. The photosensor according to  claim 14 , wherein a plurality of at least one of said source and drain electrodes is provided. 
     
     
       21. The photosensor according to  claim 14 , wherein one of said source and drain electrodes is arranged between adjacent ones of said channel regions. 
     
     
       22. A photosensor comprising: 
       a first gate electrode;  
       a first gate insulating film provided above said first gate electrode;  
       source and drain electrodes provided above said first gate insulating film;  
       a plurality of semiconductor layers provided between said source and drain electrodes, and each having a channel region, said channel regions being arranged so that there is distance between the channel regions to prevent an electric field between said source and drain electrodes from concentrating;  
       first and second impurity doped layers respectively connected to the source and drain electrodes, and separated from each other such that the first and second impurity doped layers define the channel region therebetween in each of the semiconductor layers, and such that a distance between the first and second impurity doped layers is constant at any part of the channel region for matching a length of the channel region;  
       a second gate insulating film provided above said semiconductor layer; and  
       a second gate electrode provided above said second gate insulating film.  
     
     
       23. A photosensor comprising: 
       a first gate electrode;  
       a first gate insulating film provided above said first gate electrode;  
       source and drain electrodes provided above said first gate insulating film;  
       a plurality of semiconductor layers provided between said source and drain electrodes, and each having a plurality of channel regions separated from each other so as to prevent an electric field between said source and drain electrodes from concentrating;  
       first and second impurity doped layers respectively connected to the source and drain electrodes, and separated from each other such that the first and second impurity doped layers define the channel region therebetween in each of the semiconductor layers, and such that a distance between the first and second impurity doped layers is constant at any part of the channel region for matching a length of the channel region;  
       a second gate insulating film provided above said semiconductor layers; and  
       a second gate electrode provided above said second gate insulating film.